Treatment of cellulose organic ester yarns



Patented May 15, 1945 TREATMI ENT F CELLULOSE ORGANIC ESTER. YARNS Paul W. Morgan, Kenmore, N. Y., assignor to E. I.

du Pont de Nemours & Company, Wilmington, DeL, a corporation of Delaware No Drawing. Application August 10, 1943, Serial No. 498,096

1 Claim.

This invention relates to the crinkling of yarns, filaments or fibers comprised of organic acid esters of cellulose. More particularly, the invention relates to the crinkling of cellulose acetate filaments or fibers.

The principal object of this invention is to provide a simple, relatively inexpensive method for imparting a tight, intense crinkle to yarns,

filaments and fibers of organic acid esters of cellulose. Other objects will be apparent from the description that follows.

I have found that crinkle of the desired high intensity is produced in yarns, filaments and fibers of organic acid esters of cellulose, such as cellulose acetate, by subjecting these structures, while in the substantially relaxed condition, 1. e., in a condition permitting free shrinkage, to the action of an aqueous solution of an alkyl ether alcohol of the general formula:

whereinR is an alkyl radical containing not more than carbon atoms, and R is a radical of the group consisting of C2H4OH and radicals, maintained at a suitable concentration and at a suitable temperature within ranges hereinafter specified.

Of the alkyl ether alcohols suitable for the purposes of my invention, the alkyl ethers of ethylene glycol wherein the alkyl group contains from 2 to 4 carbons are preferred. As examples of specific ether alcohols falling within this preferred group may be mentioned mono-butyl ether of ethylene glycol, mono-isopropyl ether of ethylene glycol, and mono-ethyl ether of ethylene glycol. Other specific compounds in the general class are mono-ethyl ether of diethylene glycol, mono-butyl ether of di-ethylene glycol, and mono-methyl ether of ethylene glycol.

The concentration of the alkyl ether alcohol in water may vary from as low as 2% by volume, for the most active members of the class, to as much as 50% by volume for the less active alkyl ether alcohols. Aqueous solutions containing about 1 by volume of an alkyl ether alcohol are preferred.

The temperature of treatment is important and should be within the range of from 40 to 90 C. With higher concentrations and using the more active substituted glycols, it is possible to wor in the lower portion of this temperature range with excellent results, while when using materials that are not so active or when using relatively dilute solutions, it is generally desirable to oper-' ate with a temperature in the upper portion of the range.

Any suitable expedient may be used to bring the yarn, filament or fiber into intimate contact with the treating solution. For example, skeins of yarn or staple fiber in the form of a loose mass may be immersed in a bath of the treating fluid, or yarn, filament Ibundles, or rovings or slivers of staple maybe run through the treating fluid While passing from one point to another in a continuous operation. It is essential, however, that the arn, filament or fiber be substantially free of tension, i. e. relaxed,.while in the treating bath for at this stage the structure be ing treated must be permitted to shrink freely.

While, in view of the present stateof the art, my invention has its most important commercial application in connection with the crinkling of yarns, filaments and fibers of cellulose acetate, it will be understood that it is useful, with like effect, in the treatment of other organic acid esters of cellulose, such as cellulose propionate, cellulose butyrate, cellulose acetopropionate, cellulose acetobutyrate, and the like.

To further illustrate this invention without any intention of being limited thereby, the following specific examples are given.

Example I A skein 01120 denier perv filament cellulose acetate yarn was immersed in a bath of 10% (by volume) aqueous mono-butyl ether ofethylene glycol'at C. and allowed to contract freely. Extensive crinkling took place almost immediately. After 10 minutes, the skein was removed, pressed free of excess liquid in such a way as not to put tension on the fibers,,rinsed with cool water and dried in warm air without tension. The yarn had a very good crimp, a wooly hand, and good luster. The yarn had shrunk to the extent of about 40% of the original length.

Example II Five-inch, opened staple from 2 denier per filament cellulose acetate was treated with a 10% (by volume) aqueous mono-butyl ether of ethylene glycol at 55 C. as described in Example I. A wooly, lustrous staple with a soft hand was produced.

Example III A skein of 20 denier per filament cellulose acetate was'placed in a 10% (by volume) "aqueous mono-isopropyl ether of ethylene glycol at C. without tension for 5-minutes. Crinkling took place at once. The crinkled skein was finished as in Example I. A very good crinkle was produced.

Example IV A skein of 20 denier per filament cellulose acetate yarn was placed in a 10% (by volume) aqueous mono-butyl ether of diethylene glycol at 65 C. without tension for 5 minutes. The filaments acquired considerable crinkle although they did not become so intensely crinkled as in Example I. In this case, the shrinkage in the original length was about 27%.

Asmany apparently widely different embodiments of this invention may be made without de- PAUL W. MORGAN. 

